Introduction
Background
The most common mass in the popliteal fossa, Baker cyst, also termed popliteal cyst, results from fluid distention of the gastrocnemio-semimembranosus bursa. The eponym honors the work of Dr William Morrant Baker. In 1877, Baker described 8 cases of periarticular cysts caused by synovial fluid that had escaped from the knee joint and formed a new sac outside the joint.1 The common underlying conditions were osteoarthritis and Charcot joint.2
Axial, T2-weighted magnetic resonance image of the knee shows effusion, synovial proliferation (white arrowhead), and a Baker cyst that contains debris (black arrowhead).
Contrast-enhanced, axial computed tomography (CT) scan of the knee shows multiple gaslike lucencies within a Baker cyst and synovial enhancement.
Anteroposterior radiograph of the knee shows uniform joint-space loss in the medial and lateral knee compartments without osteophytosis. A Baker cyst is seen medially (arrowhead).
This chapter reviews Baker cyst anatomy, prevalence, complications, and treatment, as well as the cyst's association with certain medical conditions and the differential diagnoses of popliteal masses. Emphasis is placed on the radiologic significance of a Baker cyst and its appearance on different imaging modalities.
Recent cases and studies
Chatzopoulos et al found that Baker's cysts are a common ultrasonographic finding in knees with chronic osteoarthritic pain and also found that they are associated with synovial inflammation and its grade. Baker's cysts were identified in 89 of 328 chronic osteoarthritic knees (27%), but only 1 cyst was found in 54 nonosteoarthritic knees (2%). Abnormal and intense tracer accumulations in early-phase bone scintigraphy were also significantly more frequent in osteoarthritic knees with Baker's cysts than in those without Baker's cysts.8
Centeno et al described a 52-year-old man with a posterior horn of the medial meniscus tear and a large Baker's cyst in whom conservative care and drainage had failed but in whom sclerotherapy subsequently succeeded. Three injections of 12.5% dextrose and anesthetic with sodium morrhuate were injected intra-articularly into the right knee after drainage, and the cyst was shown to have resolved on postoperative imaging by MRI and on physical examination.20
Pathophysiology
A Baker cyst is a synovial cyst that is located posterior to the medial femoral condyle, between the tendons of the medial head of the gastrocnemius and semimembranosus muscles. It usually communicates with the joint by way of a slitlike opening at the posteromedial aspect of the knee capsule just superior to the joint line. An extension of the knee joint, a Baker cyst is lined with a true synovium. Baker cysts range in size from 1-40 cm3 (median 3 cm3).3,4A Baker cyst may serve as a protective mechanism for the knee. Intrinsic intra-articular disorders cause joint effusion. The knee effusion is displaced into the Baker cyst, thus reducing potentially destructive pressure in the joint space. Jayson and Dixon postulated that joint effusion and fibrin are pumped from the knee joint into the Baker cyst but not in the reverse direction, because of a valvelike communication, such as a ball valve or a Bunsen valve (see Image below and Image 1 in Multimedia).5
Valvular mechanism of Baker cyst. Effusion and fibrin are pumped (large arrows) into the Baker cyst (long, thin arrows). In the Bunsen-valve mechanism, the enlarging Baker cyst exerts mass effect (feathered arrow) on the slitlike communication between the joint and the cyst, trapping effusion. In the ball-valve mechanism, fibrin serves as a 1-way valve that prevents the effusion's return to the knee joint. Trapped effusion is reabsorbed through the semipermeable membrane (short, thin arrows), leaving behind concentrations of fibrin. (MFC: medial femoral condyle; MTP: medial tibial plateau; G: medial head of gastrocnemius muscle; SM: semimembranosus muscle)
In the ball-valve mechanism, effusion is pumped from the knee joint into the Baker cyst, but fibrin acts as a 1-way valve that blocks the effusion's return to the knee joint. In the Bunsen-valve mechanism, the enlarging Baker cyst exerts mass effect on the slitlike opening between the joint and the cyst, trapping effusion. The trapped effusion is reabsorbed through the semipermeable membrane, leaving behind concentrations of fibrin. This explains the difficulty of aspirating the thick, glutinous contents of these cysts. Rauschning and Lindgren studied 41 patients with Baker cysts using arthrography, arthroscopy, or arthrotomy.6 Their study suggested that Baker cysts may form by the following 2 mechanisms:
- A primary, or idiopathic, cyst has a valvular connection with the joint cavity. Membranes, synovial bands, and folds were seen in all valvular cases in Rauschning and Lindgren's study. Scarring and irritation may create these folds in primary cysts. Alternatively, the synovial bands may be remnants of connective tissue interposed between the joint and bursal cavity. Idiopathic cysts usually are seen in young patients without symptoms. Cyst contents usually are viscous.
- A secondary, or symptomatic, cyst communicates freely with the knee joint and contains synovial fluid of normal viscosity. Secondary cysts reveal underlying articular disorders, which was demonstrated in 14 of 41 patients (34%) with Baker cysts in Rauschning and Lindgren's study. Associated articular disorders in the study included osteoarthritis, rheumatoid arthritis (RA), psoriatic arthritis, nonspecific synovitis, meniscal tears, and chondromalacia patellae.
Frequency
United States
The prevalence of Baker cysts depends on patient population and imaging modality, as shown in Tables 1 and 2 (see below).
Table 1. Prevalence of Baker Cysts Based on Diagnostic Modalities
Open table in new window
Table
| Diagnostic Modalities | Prevalence, % |
| Magnetic resonance imaging (MRI) | 5-18 |
| Cadaveric dissections | 30 |
| Arthroscopy | 37 |
| Ultrasound | 40-42 |
| Arthrography | 5-46 |
| Diagnostic Modalities | Prevalence, % |
| Magnetic resonance imaging (MRI) | 5-18 |
| Cadaveric dissections | 30 |
| Arthroscopy | 37 |
| Ultrasound | 40-42 |
| Arthrography | 5-46 |
Table 2. Prevalence of Baker Cysts Based on Patient Populations
Open table in new window
Table
| Patient Populations | Prevalence, % |
| Rheumatoid Arthritis | 5-58 |
| Osteoarthritis | 42 |
| Internal derangements | 5-18 |
| Patient Populations | Prevalence, % |
| Rheumatoid Arthritis | 5-58 |
| Osteoarthritis | 42 |
| Internal derangements | 5-18 |
Mortality/Morbidity
Refer to Special Concerns for a detailed discussion.
Race
No racial predilection exists.
Sex
No sex predilection exists.
Anatomy
Refer to Pathophysiology for a detailed discussion.
Presentation
Table 3 lists the most common symptoms in patients with a Baker cyst, as found in a study of 38 patients by Bryan and colleagues.7
Table 3. Symptoms of Baker Cyst
Open table in new window
Table
| Symptoms | Frequency | |
| Popliteal mass or swelling | 29/38 | 76% |
| Aching | 12/38 | 32% |
| Knee effusion | 12/38 | 32% |
| Thrombophlebitis | 5/38 | 13% |
| Clicking of the knee | 4/38 | 11% |
| Buckling of the knee | 4/38 | 11% |
| Locking of the knee | 1/38 | 3% |
| Symptoms | Frequency | |
| Popliteal mass or swelling | 29/38 | 76% |
| Aching | 12/38 | 32% |
| Knee effusion | 12/38 | 32% |
| Thrombophlebitis | 5/38 | 13% |
| Clicking of the knee | 4/38 | 11% |
| Buckling of the knee | 4/38 | 11% |
| Locking of the knee | 1/38 | 3% |
In the study, a popliteal mass was the most common presenting complaint or symptom. A significant number of patients (13%) had pseudothrombophlebitis, a syndrome in which symptoms simulate those of deep venous thrombosis (DVT). Therefore, DVT should be excluded in patients with Baker cyst and leg swelling.
Medical conditions associated with Baker cysts, in descending order of frequency, are as follows:
- Arthritides
- Osteoarthritis
- RA
- Juvenile RA
- Gout
- Reiter syndrome
- Psoriasis
- Systemic lupus erythematosus
- Internal derangement (meniscal tears, anterior cruciate ligament [ACL] tears, osteochondral fractures)
- Infection (septic arthritis, tuberculosis)
- Chronic dialysis
- Hemophilia
- Hypothyroidism
- Pigmented villonodular synovitis
- Sarcoidosis
Arthritis is the most common condition associated with Baker cysts, with osteoarthritis probably being the most frequent cause among the arthritides.8 Although the prevalence of Baker cysts in patients with inflammatory arthritis is higher than in patients with osteoarthritis, osteoarthritis is much more common than inflammatory arthritis. Using ultrasonography, Fam and colleagues found that 21 of 50 patients (42%) with osteoarthritis had Baker cysts.9 Bilateral cysts were seen in 8 patients (16%). The occurrence of Baker cysts relates directly to the presence of knee effusion and the severity of the osteoarthritis.
In 99 consecutive patients with RA, Andonopoulos and coauthors demonstrated Baker cysts on ultrasonograms of 47 patients (48%).10 Twenty of the 99 patients (20%) had bilateral cysts. Of 198 knees, 67 (34%) had Baker cysts, yet only 29 cysts (43%) were diagnosed clinically.
Baker cysts appear much less frequently in children than in adults. The prevalence of Baker cysts in asymptomatic children examined ultrasonographically was 2.4%. The prevalence of Baker cyst in children undergoing MRI examination of the knee was 6.3%. None of the children with Baker cyst demonstrated an associated ACL or meniscal tear. Four patients (8%) had osteochondritis dissecans (n = 2), septic arthritis (n = 1), or juvenile RA (n = 1). In most children with Baker cysts (82%), the cysts disappeared without intervention (84%) or caused no symptoms (16%). However, in children with arthritis, Baker cysts are common.
In a study of 44 children with knee arthritis, ultrasonography detected a Baker cyst in 27 children (61%), most of whom (80%) had juvenile RA.11 The remaining causes of arthritis in the study included spondyloarthropathy, psoriatic arthritis, septic arthritis, and systemic lupus erythematosus. Cysts were followed prospectively with serial ultrasonography for 18-24 months. Cysts resolved with the resolution of suprapatellar effusion. Reports of Baker cyst associated with gout, Reiter syndrome, psoriasis, and systemic lupus erythematosus exist. The common underlying pathology for these medical conditions is synovial proliferation with effusion.
Arthrography is more sensitive than ultrasonography in detecting Baker cysts. In 24 patients with a possible Baker cyst, arthrography of both knees was performed immediately after ultrasonography. The latter detected a cyst in 19 of the 48 knees (40%), while arthrography demonstrated a cyst in 22 knees (46%). The increased sensitivity of arthrography is probably the result of its ability to distend the bursa.
Guerra and colleagues found a 30% incidence of popliteal bursa in cadaveric anatomic dissection of older patients.12 Using diagnostic arthroscopy, Johnson and coauthors demonstrated a 37% incidence of popliteal bursa.13 The incidence of Baker cysts detected through MRI of the knee varies (5-18%) according to the patient population. Initially, Fielding and colleagues reported an association between Baker cyst and tear of the medial meniscus or complete tear of the ACL.14 Stone and colleagues demonstrated that 84% of Baker cysts detected on magnetic resonance images had meniscal tears.15 Most tears were observed in the posterior horn of the medial meniscus.
Subsequently, Miller and coauthors confirmed a significant association of Baker cyst with effusion, meniscal tears, and degenerative arthropathy.16 The probability of a Baker cyst in the presence of any 1 variable (ie, association) is P = 0.08-0.10, of any 2 variables is P = 0.19-0.21, and of all 3 variables is P = 0.38. However, no association was found between Baker cyst and ACL tear.
Sansone and colleagues reviewed the incidence of associated intra-articular disorders in a series of 1001 adult patients undergoing MRI of the knee.17 They found that the most common associated lesions were meniscal tears, chondral lesions, and ACL tears.
Treatment
The treatment of Baker cysts is conservative and includes the use of nonsteroidal anti-inflammatory agents, ice, and assisted weight bearing, in addition to the correction of underlying intra-articular disorders. Internal derangements of the knee can be treated with therapeutic arthroscopy.18 Total knee arthroplasty is reserved for severe osteoarthritis.19,20
Radioactive synoviorthesis can be used to treat inflammatory arthritides and hemophilia. Prior to this treatment, arthrography should be performed to exclude a leaking Baker cyst (see Image below and Image 19 in Multimedia). A leaking Baker cyst would release radionuclide agent outside the knee joint, which is a contraindication to radioactive synoviorthesis.
Arthrography of the knee performed prior to radioactive synoviorthesis shows leakage of contrast (arrow) just superior to the sinus (arrowhead and "BB" marker).
Radionuclide agents can be instilled during arthrography after the absence of leakage, rupture, or dissection has been documented. Colloidal chromic phosphorus-32 is a common radionuclide agent used in synoviorthesis. An orthopedic surgeon may perform cyst excision when a Baker cyst is unresponsive to all other therapies.
Preferred Examination
Imaging evaluation of a Baker cyst begins with conventional radiography to detect a soft-tissue mass (see Image below and Image 2 in Multimedia), internal calcifications, displacement of an atherosclerotic popliteal artery, and the unusual case of adjacent bony involvement from a large and/or long-standing cyst.8
Anteroposterior radiograph of the knee shows uniform joint-space loss in the medial and lateral knee compartments without osteophytosis. A Baker cyst is seen medially (arrowhead).
Ultrasonography is a very helpful imaging technique in the evaluation of a popliteal mass. The modality is an easy-to-use, rapid, relatively inexpensive examination to employ in this setting. Ultrasonography determines whether the popliteal mass is a pure cystic structure or a complex cyst and/or solid mass (see Images below and Image 3, Image 4 in Multimedia).
Transverse ultrasonographic image of the knee in a patient who had recent arthroscopy shows a complex, cystic mass (arrow) in the medial aspect of popliteal fossa. The mass communicates with the knee joint (arrowhead), which is consistent with a Baker cyst.
Longitudinal ultrasonographic image of a Baker cyst in a patient who underwent recent knee arthroscopy.
Color Doppler imaging can confirm the absence of vascular flow within the mass to exclude a popliteal artery aneurysm or cystic adventitial degeneration of a popliteal artery (see Images below and Image 5, Image 6 in Multimedia).21 Ultrasonography can concomitantly exclude a coexisting DVT created by subjacent mass effect. The weakness of ultrasonography is related to the difficulty in establishing a true connection to the joint space proper, which is essential for discriminating between a Baker cyst and other potentially harmful conditions in the differential diagnosis (see the discussion on magnetic resonance evaluation, below).
Transverse ultrasonographic image of the popliteal fossa shows a complex, cystic mass (arrowhead).
Transverse color Doppler ultrasonographic image of the popliteal fossa shows multiple cysts surrounding a normal-sized popliteal artery (A), which is consistent with cystic adventitial degeneration.
The communication with the joint by way of the gastrocnemio-semimembranosus bursa is deep within the popliteal space, adjacent to the dense posterior femoral cortex. The ultrasonography probe is placed over the popliteal skin surface, and because this thin, necklike connection to the joint is anterior to the cyst, the mere presence of a large or complex Baker cyst may obscure the visualization of this connection.
Previously, Baker cysts were commonly detected by conventional arthrography or by computed tomography (CT) scanning. Arthrography demonstrates the cyst only if the iodinated contrast material that is injected into the joint during arthrography communicates with the cyst under the pressure of the injection. CT scanning can delineate a low to intermediate attenuation mass, which normally measures from 20 to -10 Hounsfield units, in the posteromedial popliteal space. CT scanning can easily delineate secondary findings, such as intracystic osseous fragments, mass effect, wall thickening, and bony erosion.
In current radiologic practice, Baker cysts are often detected on MRI evaluations of the knee (performed for any indication). Sansone and colleagues studied 1001 randomly selected patients who were submitted for a knee MRI examination; the authors reported the frequency of Baker cysts to be 4.7%, but the frequency in the literature varies. The advantages of MRI are derived from the superior soft-tissue contrast resolution that it affords and from the modality's multiplanar capability, which help to determine the extent and composition of the Baker cyst.
However, one of the most important benefits of employing MRI is the ability to use the axial plane to establish positive identification of the high – signal intensity, fluid-filled neck of the cyst that connects the cyst to the joint space (see Image below and Image 7 in Multimedia). This makes it possible to discriminate between a benign Baker cyst and one of the uncommon, but clinically important, types of cystic tumors, such as myxoid liposarcoma, that can occur in the popliteal fossa.
Axial, T2-weighted magnetic resonance image with fat saturation reveals a Baker cyst connected to the knee joint by way of a narrow neck between the tendons of the medial head of the gastrocnemius and semimembranosus muscles.
On ultrasonography, myxoid liposarcomas appear as complex, hypoechoic masses that do not meet the criteria for a simple cyst. Myxoid liposarcoma can mimic a fluid-filled cyst on T2-weighted imaging. Contrast enhancement is helpful in distinguishing cystic or necrotic lesions from solid cellular lesions.
Differential Diagnoses
Deep Venous Thrombosis, Lower Extremity
Other Problems to Be Considered
Vascular masses
- Popliteal artery aneurysm - Most common in the popliteal fossa
- Cystic adventitial degeneration of the popliteal artery - Erdheim mucoid degeneration
Nonvascular masses
- Simple Baker cyst
- Complicated Baker cyst - Characterized by internal debris (see Image 12, Image 17, Image 18 in Multimedia), septations (see Image 16 in Multimedia), or MRI signal intensity atypical for simple cyst
- Inflammatory arthritides
- Septic arthritis
- Postoperative changes - Seroma, hematoma, or abscess
- Hemorrhage within a cyst
- Hemophilic arthropathy
- Soft-tissue tumor
- Benign - Peripheral nerve sheath tumors (neurilemmoma)
- Malignant - myxoid liposarcoma (adults), lipoblastoma (children, especially < 5 y)
- Meniscal cyst - Occurs more often laterally, but medial cysts have been identified
- Ganglion cyst
- Traumatic tear of the gastrocnemius muscle
More on Baker Cyst |
 Overview: Baker Cyst |
| Imaging: Baker Cyst |
| Follow-up: Baker Cyst |
| Multimedia: Baker Cyst |
| References |
| Further Reading |
| Next Page » |
References
Baker WM. On the formation of synovial cysts in the leg in connection with disease of the knee-joint. 1877. Clin Orthop Relat Res. Feb 1994;(299):2-10. [Medline].
Pinnamaneni S, Thomas PS. Anatomy, imaging, treatment options for Baker's Cyst. Pain Physician. May-Jun 2008;11(3):376-7; author reply 377-8. [Medline].
Corten K, Vandenneucker H, Reynders P, Nijs S, Pittevils T, Bellemans J. A pyogenic, ruptured Baker's cyst induced by arthroscopic pressure pump irrigation. Knee Surg Sports Traumatol Arthrosc. Dec 16 2008;[Medline].
Fritschy D, Fasel J, Imbert JC, et al. The popliteal cyst. Knee Surg Sports Traumatol Arthrosc. Jul 2006;14(7):623-8. [Medline].
Jayson MI, Dixon AS. Valvular mechanisms in juxta-articular cysts. Ann Rheum Dis. Jul 1970;29(4):415-20. [Medline]. [Full Text].
Rauschning W, Lindgren PG. The clinical significance of the valve mechanism in communicating popliteal cysts. Arch Orthop Trauma Surg. 1979;95(4):251-6. [Medline].
Bryan RS, DiMichele JD, Ford GL Jr. Popliteal cysts. Arthrography as an aid to diagnosis and treatment. Clin Orthop Relat Res. Jan-Feb 1967;50:203-8. [Medline].
Chatzopoulos D, Moralidis E, Markou P, Makris V, Arsos G. Baker's cysts in knees with chronic osteoarthritic pain: a clinical, ultrasonographic, radiographic and scintigraphic evaluation. Rheumatol Int. Dec 2008;29(2):141-6. [Medline].
Fam AG, Wilson SR, Holmberg S. Ultrasound evaluation of popliteal cysts on osteoarthritis of the knee. J Rheumatol. May-Jun 1982;9(3):428-34. [Medline].
Andonopoulos AP, Yarmenitis S, Sfountouris H, et al. Baker's cyst in rheumatoid arthritis: an ultrasonographic study with a high resolution technique. Clin Exp Rheumatol. Sep-Oct 1995;13(5):633-6. [Medline].
Szer IS, Klein-Gitelman M, DeNardo BA. Ultrasonography in the study of prevalence and clinical evolution of popliteal cysts in children with knee effusions. J Rheumatol. Mar 1992;19(3):458-62. [Medline].
Guerra J Jr, Newell JD, Resnick D. Pictorial essay: gastrocnemio-semimembranosus bursal region of the knee. AJR Am J Roentgenol. Mar 1981;136(3):593-6. [Medline]. [Full Text].
Johnson LL, van Dyk GE, Johnson CA, et al. The popliteal bursa (Baker's cyst): an arthroscopic perspective and the epidemiology. Arthroscopy. Feb 1997;13(1):66-72. [Medline].
Fielding JR, Franklin PD, Kustan J. Popliteal cysts: a reassessment using magnetic resonance imaging. Skeletal Radiol. 1991;20(6):433-5. [Medline].
Stone KR, Stoller D, De Carli A, et al. The frequency of Baker's cysts associated with meniscal tears. Am J Sports Med. Sep-Oct 1996;24(5):670-1. [Medline].
Miller TT, Staron RB, Koenigsberg T. MR imaging of Baker cysts: association with internal derangement, effusion, and degenerative arthropathy. Radiology. Oct 1996;201(1):247-50. [Medline]. [Full Text].
Sansone V, de Ponti A, Paluello GM. Popliteal cysts and associated disorders of the knee. Critical review with MR imaging. Int Orthop. 1995;19(5):275-9. [Medline].
Ahn JH, Yoo JC, Lee SH, et al. Arthroscopic cystectomy for popliteal cysts through the posteromedial cystic portal. Arthroscopy. May 2007;23(5):559.e1-4. [Medline].
Linetsky F. Sclerotherapy for Baker's Cyst. Pain Physician. May-Jun 2008;11(3):375-6. [Medline].
Centeno CJ, Schultz J, Freeman M. Sclerotherapy of Baker's cyst with imaging confirmation of resolution. Pain Physician. Mar-Apr 2008;11(2):257-61. [Medline].
Taurino M, Rizzo L, Stella N, Mastroddi M, Conteduca F, Maggiore C, et al. Doppler ultrasonography and exercise testing in diagnosing a popliteal artery adventitial cyst. Cardiovasc Ultrasound. May 27 2009;7:23. [Medline].
Marra MD, Crema MD, Chung M, Roemer FW, Hunter DJ, Zaim S, et al. MRI features of cystic lesions around the knee. Knee. Dec 2008;15(6):423-38. [Medline].
Acebes JC, Sánchez-Pernaute O, Díaz-Oca A, et al. Ultrasonographic assessment of Baker's cysts after intra-articular corticosteroid injection in knee osteoarthritis. J Clin Ultrasound. Mar-Apr 2006;34(3):113-7. [Medline].
Barisic I, Ljutic D, Vlak T, et al. Laboratory and sonographic findings in dialyzed patients with bilateral chronic knee pain versus dialyzed asymptomatic patients. Coll Antropol. Jun 2007;31(2):489-94. [Medline].
Gompels BM, Darlington LG. Grey scale ultrasonography and arthrography in evaluation of popliteal cysts. Clin Radiol. Sep 1979;30(5):539-45. [Medline].
Corten K, Vandenneucker H, Reynders P, Nijs S, Pittevils T, Bellemans J. A pyogenic, ruptured Baker's cyst induced by arthroscopic pressure pump irrigation. Knee Surg Sports Traumatol Arthrosc. Mar 2009;17(3):266-9. [Medline].
Anderson CJ, Cannon GW, Andrews JM. Gouty tophus presenting as "pseudo-Baker's cyst". J Rheumatol. Sep 1989;16(9):1281-2. [Medline].
Chaudhuri R, Salari R. Baker's cyst simulating deep vein thrombosis. Clin Radiol. Jun 1990;41(6):400-4. [Medline].
Cuende E, Barbadillo C, E-Mazzucchelli R. Candida arthritis in adult patients who are not intravenous drug addicts: report of three cases and review of the literature. Semin Arthritis Rheum. Feb 1993;22(4):224-41. [Medline].
De Greef I, Molenaers G, Fabry G. Popliteal cysts in children: a retrospective study of 62 cases. Acta Orthop Belg. Jun 1998;64(2):180-3. [Medline].
De Maeseneer M, Debaere C, Desprechins B. Popliteal cysts in children: prevalence, appearance and associated findings at MR imaging. Pediatr Radiol. Aug 1999;29(8):605-9. [Medline].
Dunlop D, Parker PJ, Keating JF. Ruptured Baker's cyst causing posterior compartment syndrome. Injury. Oct 1997;28(8):561-2. [Medline].
Fergusson C, Burge P. An unusual loose body in the knee. Clin Orthop Relat Res. May 1986;(206):233-5. [Medline].
Goldberg RP, Genant HK. Calcified bodies in popliteal cysts: a characteristic radiographic appearance. AJR Am J Roentgenol. Nov 1978;131(5):857-9. [Medline].
Gompels BM, Darlington LG. Evaluation of popliteal cysts and painful calves with ultrasonography: comparison with arthrography. Ann Rheum Dis. Aug 1982;41(4):355-9. [Medline]. [Full Text].
Ha TV, Kleinman PK, Fraire A. MR imaging of benign fatty tumors in children: report of four cases and review of the literature. Skeletal Radiol. Jul 1994;23(5):361-7. [Medline].
Hammoudeh M, Siam AR, Khanjar I. Anterior dissection of popliteal cyst causing anterior compartment syndrome. J Rheumatol. Jul 1995;22(7):1377-9. [Medline].
Houston CS. Pitfalls to avoid. When is a fabella not a fabella?. J Can Assoc Radiol. Sep 1978;29(3):193. [Medline].
Kattapuram SV. Case report 181: calcified popliteal cyst (Baker cyst). Skeletal Radiol. Jan 1982;7(4):279-81. [Medline].
Krome J, de Araujo W, Webb LX. Acute compartment syndrome in ruptured Baker's cyst. J South Orthop Assoc. 1997;6(2):110-4. [Medline].
Langsfeld M, Matteson B, Johnson W, et al. Baker's cysts mimicking the symptoms of deep vein thrombosis: diagnosis with venous duplex scanning. J Vasc Surg. Apr 1997;25(4):658-62. [Medline].
Lepore L, Rabusin M, Pennesi M, et al. Bilateral Baker's cyst in a patient with psoriatic arthritis of pediatric onset. Clin Exp Rheumatol. Jan-Feb 1996;14(1):109-10. [Medline].
Mangiafico RA, Santonocito M, Mandalà ML, et al. [Pseudothrombophlebitis due to an expansive popliteal cyst associated with Reiter's syndrome]. Minerva Med. Sep 1995;86(9):391-4. [Medline].
Marques Filho J. [Pseudothrombophlebitis syndrome in Reiter's syndrome]. Rev Assoc Med Bras. May-Jun 1995;41(3):252-4. [Medline].
McLeod BC, Charters JR, Straus AK. Gas-like radiolucencies in a popliteal cyst. Rheumatol Int. 1983;3(3):143-4. [Medline].
Molpus WM, Shah HR, Nicholas RW, et al. Case report 731. Complicated Baker's cyst. Skeletal Radiol. 1992;21(4):266-8. [Medline].
Munk PL, Vellet AD, Levin MF. Leaking Baker's cyst detected by magnetic resonance imaging. Can Assoc Radiol J. Apr 1993;44(2):125-8. [Medline].
Onetti CM, Gutiérrez E, Hliba E, et al. Synoviorthesis with 32P-colloidal chromic phosphate in rheumatoid arthritis--clinical, histopathologic and arthrographic changes. J Rheumatol. Mar-Apr 1982;9(2):229-38. [Medline].
Petros DP, Hanley JF, Gilbreath P, et al. Posterior compartment syndrome following ruptured Baker's cyst. Ann Rheum Dis. Nov 1990;49(11):944-5. [Medline]. [Full Text].
Reilly PA, Maddison PJ. Painful, swollen calf in a patient with SLE. Br J Rheumatol. Aug 1987;26(4):319-20. [Medline].
Rennebohm RM, Towbin RB, Crowe WE. Popliteal cysts in juvenile rheumatoid arthritis. AJR Am J Roentgenol. Jan 1983;140(1):123-5. [Medline]. [Full Text].
Rubin BR, Gupta VP, Levy RS. Anaerobic abscess of a popliteal cyst in a patient with rheumatoid arthritis. J Rheumatol. Sep-Oct 1982;9(5):733-4. [Medline].
Schultz E, Rosenblatt R, Mitsudo S. Detection of a deep lipoblastoma by MRI and ultrasound. Pediatr Radiol. 1993;23(5):409-10. [Medline].
Scott WN, Jacobs B, Lockshin MD. Posterior compartment syndrome resulting from a dissecting popliteal cyst. Case report. Clin Orthop Relat Res. Jan-Feb 1977;(122):189-92. [Medline].
Seil R, Rupp S, Jochum P. Prevalence of popliteal cysts in children. A sonographic study and review of the literature. Arch Orthop Trauma Surg. 1999;119(1-2):73-5. [Medline].
Siegel HJ, Luck JV Jr, Siegel ME. Hemarthrosis and synovitis associated with hemophilia: clinical use of P-32 chromic phosphate synoviorthesis for treatment. Radiology. Jan 1994;190(1):257-61. [Medline]. [Full Text].
Simpson FG, Robinson PJ, Bark M. Prospective study of thrombophlebitis and "pseudothrombophlebitis". Lancet. Feb 16 1980;1(8164):331-3. [Medline].
Sung MS, Kang HS, Suh JS. Myxoid liposarcoma: appearance at MR imaging with histologic correlation. Radiographics. Jul-Aug 2000;20(4):1007-19. [Medline]. [Full Text].
Takano Y, Oida K, Kohri Y, et al. Is Baker's cyst a risk factor for pulmonary embolism?. Intern Med. Nov 1996;35(11):886-9. [Medline]. [Full Text].
Toolanen G, Lorentzon R, Friberg S. Sonography of popliteal masses. Acta Orthop Scand. Jun 1988;59(3):294-6. [Medline].
Volteas SK, Labropoulos N, Leon M, et al. Incidence of ruptured Baker's cyst among patients with symptoms of deep vein thrombosis. Br J Surg. Mar 1997;84(3):342. [Medline].
Wallner RJ, Dadparvar S, Croll MN, et al. Demonstration of an infected popliteal (Baker's) cyst with three-phase skeletal scintigraphy. Clin Nucl Med. Mar 1985;10(3):153-5. [Medline].
Wilson AJ, Ford LT, Gilula LA. Migrating mouse: a sign of dissecting popliteal cyst. AJR Am J Roentgenol. Apr 1988;150(4):867-8. [Medline]. [Full Text].
Further Reading
Related eMedicine topics
Osteoarthritis
Neuropathic Arthropathy (Charcot Joint)
Arthrocentesis, Knee
The Approach to the Painful Joint
Patellofemoral Joint Syndromes
Cystic Lesions About the Knee
Knee Injury, Soft Tissue
Clinical guideline
Ultrasonographic examinations: indications and preparation of the patient.
Finnish Medical Society Duodecim - Professional Association. 2000 Apr 18 (revised 2007 Jan 11). Various pagings. NGC:005501
Keywords
Baker cyst, Baker's cyst, popliteal cyst, popliteal bursa, gastrocnemio-semimembranosus bursa, gastrocnemio-semimembranous bursa, gastrocnemiosemimembranosus bursa, gastrocnemiosemimembranous bursa
